Vulnerability · CVE-2026-21913
An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based at
Published Jan 15, 2026 · catalog updated Jan 15, 2026 · Juniper Networks Junos OS
Last checked Oct 30, 2026. A connected source was read within the last 7 days.
Check if you run it
No confirmed exploitation is on record for CVE-2026-21913. EPSS is 0.41%. Act only if a listed version of Juniper Networks Junos OS is installed.
Gaps on this record
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
Same product and reporting
- CVE-2026-102185 · High
- CVE-2026-102184 · High
- CVE-2026-102183 · High
- CVE-2026-102182 · Critical
- CVE-2026-102180 · High
- Severity
- High8.7
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- 0.41%
- Remediation
- Version ranges on file
- Affected products
- vendor Juniper Networks Junos OS 24.4 <24.4R2
An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On EX4000 models with 48 ports (EX4000-48T, EX4000-48P, EX4000-48MP) a high volume of traffic destined to the device will cause an FXPC crash and restart, which leads to a complete service outage until the device has automatically restarted. The following reboot reason can be seen in the output of 'show chassis routing-engine' and as a log message: reason=0x4000002 reason_st
Are you affected?
Enter the version you run. The result uses only the ranges stored on this record.
The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.
- vendor Juniper Networks Junos OS 24.4 <24.4R224.4 <24.4R2
How to fix CVE-2026-21913
Upgrade
CVE-2026-21913 lists a fix boundary at 24.4R2. Compare the installed build with that boundary before you change production.
Version check
Seen in 24.4 <24.4R2
Advisory
Open the cve_org record and follow its fix.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
No confirmed exploitation is on record for CVE-2026-21913. EPSS is 0.41%. Act only if a listed version of Juniper Networks Junos OS is installed.
Which versions are affected?
Compare what you have installed with Juniper Networks Junos OS 24.4 <24.4R2 24.4 <24.4R2. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
No weakness class is stored. EPSS 0.41%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
No public source repository is identified for this product.
Timeline
Detection, updates, and resolution for this record.
Jan 15, 2026 · EUVD
Detected
An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On EX4000 models with 48 ports (EX4000-48T, EX4000-48P, EX4000-48MP) a high volume of traffic destined to the device will cause an FXPC crash and restart, which leads to a compl
Jan 15, 2026 · EUVD
Updated
An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On EX4000 models with 48 ports (EX4000-48T, EX4000-48P, EX4000-48MP) a high volume of traffic destined to the device will cause an FXPC crash and restart, which leads to a compl
Sources
- CVE.orgVulnerability recordCVE-2026-21913
Official CVE identifier
cve.org - FIRST EPSSExploitation probabilityCVE-2026-21913
30-day exploitation probability 0.41%
first.org - EUVDVulnerability recordEUVD-2026-2688
An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On EX4000 models with 48 ports (EX4000-48T, EX4000-48P, E
euvd.enisa.europa.eu
References
Freshness
Last verified in this catalog Oct 30, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.
- CVE.orgOct 30, 2026
- FIRST EPSSOct 30, 2026
- EUVDOct 30, 2026